A method for producing a carbon nanotube sheet by using a forest of carbon nanotubes has been disclosed (see PCT International Application No. 2007-015710, for example). In the method for producing a carbon nanotube sheet disclosed in PCT International Application No. 2007-015710, carbon nanotubes grown on the surface of a growth substrate by chemical vapor deposition (CVD) are drawn with a jig, and then, the drawn carbon nanotubes in a ribbon shape are arranged on a base to form a carbon nanotube sheet. The carbon nanotube sheet is then infiltrated together with the base into, for example, acetone, for a densification process. The carbon nanotube sheet is thus modified to have increased strength and increased light transmittance.